Glyphosate is still safe, and the IARC is still full of fertilizer

Glyphosate is the world’s most popular agricultural herbicide. Why? Because it’s safe and very effective. I use it myself on invasive species at my property.

Yet, in virtually any discussion that mentions glyphosate, either online or in person, somebody is certain to counter that it was classified as a carcinogen by the IARC, and probably also that it causes Non-Hodgkins lymphoma. Both are false.

Here are 4 reasons why you can dismiss it:

1. The IARC classification (2A) is NOT as a carcinogen!

People are just crazy wrong about this. The IARC’s list of carcinogens is called Group 1; glyphosate is Group 2A, “probable carcinogens,” although no evidence is needed for this classification. To be precise, here is the definition of 2A under which glyphosate is included:

This category generally applies if there is strong evidence that the agent belongs, based on mechanistic considerations, to a class of agents for which one or more members have been classified in group 1 or group 2A.

It means that some other compound to which glyphosate bears some “mechanistic resemblance” is a carcinogen or probable carcinogen. The classification says nothing about glyphosate itself.

Other things listed in 2A include being a hairdresser, working night shifts, and drinking hot beverages.

2. The IARC classifications are not safety assessments.

IARC is a hazard assessment, not a risk assessment. These are very different, and the difference is very important.

If a giant meteorite was headed straight for you, that would be a very hazardous situation — so IARC should give that an extremely high score. However, your risk of ever being hit by a meteorite is astronomically low.

When we assess a compound’s safety, we look at the risk, not at the hazard. Here is how the National Pesticide Information Center puts it:

Some agencies place more weight on hazard than risk. For example, the International Agency for Research on Cancer (IARC) works to identify the causes of cancer in humans. By only identifying the potential for harm, it does not consider risks to individuals in terms of both hazard and exposure. It is similar to recognizing that a car is a hazard, without exploring how the car is being used.

3. The WHO’s actual finding on glyphosate is that it’s safe.

JMPR (Joint FAO/WHO Meeting on Pesticide Residues) is the WHO’s body that gives risk assessment for compounds — not IARC. Here is from their latest re-assessment of glyphosate from 2016, which came after the IARC’s classification:

The overall weight of evidence indicates that administration of glyphosate and its formulation products at doses as high as 2000 mg/kg body weight by the oral route, the route most relevant to human dietary exposure, was not associated with genotoxic effects in an overwhelming majority of studies conducted in mammals… The Meeting concluded that glyphosate is unlikely to be genotoxic at anticipated dietary exposures… in view of the absence of carcinogenic potential in rodents at human-relevant doses and the absence of genotoxicity by the oral route in mammals, and considering the epidemiological evidence from occupational exposures, the Meeting concluded that glyphosate is unlikely to pose a carcinogenic risk to humans from exposure through the diet.

2000 mg/kg!!! For the average 80 kg adult, a dose of pure glyphosate found to be safe is 160 grams — that’s over a third of a pound, enough to fill a six-ounce glass.

4. Glyphosate’s inclusion by IARC has been criticized as corrupt AF.

All three of these are serious red flags:

• Reuters and other outlets later reported that a key scientist, Aaron Blair, had access to the then-unpublished Agricultural Health Study data showing no carcinogenic effect — and did not disclose it to the IARC panel, a significant omission;¹

• There were allegations of post-meeting edits to the monograph, made in secret, that changed conclusions in the final published version;²

• Several scientists involved had consulting relationships with plaintiff attorneys in glyphosate litigation, raising serious conflict-of-interest questions.³

Every other food safety body on Earth reviewed the same data as the IARC, and all came to the opposite conclusion. Did they do something different? Why yes, they did. Here are three things that critics of the IARC have pointed out:

• The other agencies assessed the risk instead of the hazard, importantly including actual human exposure levels from agricultural and dietary sources;⁴

• The other agencies used the full data set, including unpublished industry studies that met regulatory standards. IARC excluded those, which is methodologically suspicious;⁵

• The other agencies weighted epidemiological evidence more accurately — IARC leaned heavily on the Hardell group studies, which “involve exposure scenarios that are so infrequent... that they would not be given credence in other areas of epidemiology.” Other agencies used the larger and sounder Agricultural Health Study, a prospective cohort of ~89,000 licensed pesticide applicators, which found no link between glyphosate and Non-Hodgkin’s lymphoma.⁶

Nevertheless…

I have no illusions that these facts will change any minds; the organic industry marketing machine is powerful and holds a firm grip on the brains of seemingly most Americans. Once people have gotten the idea in their heads that our safest and most modern agricultural methods and materials are not the result of accumulated knowledge, but are instead the result of a dark conspiracy of evil corporations that want to make us all sick, that idea is there to stay.

Ideas are powerful; facts are boring.

Updated May 26 2026 to refer to glyphosate as an herbicide rather than a pesticide. Pesticide is a blanket term including both herbicides and insecticides; glyphosate’s intended use is as an herbicide. BD

See also:

• Skeptoid #676 Glyphosate and Behavioral Economics — addresses how the misinformation became so much more widespread than the facts

• Skeptoid #759 Percy Schmeiser vs Monsanto — debunks the false belief that Monsanto habitually sued its customers

• Skeptoid #524 Colony Collapse Disorder — discusses the true current status and causes of bee population collapse (as of 2016), and to what degree pesticides contributed

1. https://www.reuters.com/investigates/special-report/who-iarc-glyphosate/

2. https://www.investing.com/news/stock-market-news/in-glyphosate-review-who-cancer-agency-edited-out-noncarcinogenic-findings-544253

3. https://www.courthousenews.com/roundup-trial-sees-doubt-cast-on-cancer-expert/

4. https://www.epa.gov/ingredients-used-pesticide-products/glyphosate

5. https://link.springer.com/article/10.1007/s00204-017-1962-5

6. https://www.sciencedirect.com/science/article/pii/S2590113323000044